1. Field of the Invention
This invention relates to the use of 2,5-diacyloxy-2,5-dihydrofurans as activators for inorganic peroxides and to detergents, cleaning preparations and disinfectants containing these activators.
2. Discussion of Related Art
Inorganic per compounds, more particularly hydrogen peroxide and solid per compounds which dissolve in water with evolution of hydrogen peroxide, such as sodium perborate and sodium carbonate perhydrate, have long been used as oxidizing agents for disinfection and bleaching purposes. The oxidizing effect of these substances in dilute solutions depends to a large extent on temperature. Thus, with H.sub.2 O.sub.2 or perborate, for example, sufficiently rapid bleaching of soiled textiles in alkaline bleaching liquors is only achieved at temperatures above approximately 80.degree. C. At lower temperatures, the oxidizing effect of the inorganic per compounds can be improved by addition of so-called activators, for which numerous proposals have been made in the literature, above all from the classes of N- or O-acyl compounds, for example polyacylated alkylenediamines, more particularly tetraacetyl ethylenediamine, acylated glycol urils, more particularly tetraacetyl glycol uril, N-acylated hydantoins, hydrazides, triazoles, urazoles, diketopiperazines, sulfuryl amides and cyanurates, also carboxylic anhydrides, more particularly phthalic anhydride, carboxylic acid esters, more particularly sodium isononanoyl phenyl sulfonate and acylated sugar derivatives, such as pentaacetyl glucose. The bleaching effect of water-based peroxide liquors can be increased by addition of these substances to such an extent that substantially the same effects are obtained at temperatures as low as 60.degree. C. as are obtained with the peroxide liquor alone at 95.degree. C.
In the efforts being made to develop energy-saving washing and bleaching processes, application temperatures well below 60.degree. C. and, more particularly, below 45.degree. C. down to the temperature of cold water have acquired increasing significance in recent years.
Unfortunately, the effect of hitherto known activators clearly diminishes at these low temperatures. Accordingly, there has been no shortage of attempts to develop more effective activators for this temperature range although there has not yet been any evidence of real success. The problem addressed by the present invention also was to improve the oxidizing and bleaching effect of inorganic per compounds at low temperatures below 80.degree. C. and, more particularly, in the range from about 15.degree. C. to 45.degree. C.